Hydraulic brake cylinder



April 6, 94 1.. E. LA BRIE 2,196,995

HYDRAULIC BRAKE CYLINDER Filed Sept. 9, 1955 2 Sheets-Sheet 1 f HINVENTOR. 1006525 ZHfi/Z/F f HI BY ATTORNEY Patented Apr. 16, 1940xUNlTED STATES PATENT OFFICE HYDRAULIC BRAKE ornmnna Ludger a. La Brie,South Bend. ma, assignmto Bendix Products Corporation, South Bend, Ind.,a corporation of Indiana Application September 9, 1935, Serial No.39,738

4 Claims. (01. (so-54.6) Y

This invention relates to fluid power cylinders and is especiallyapplicable to power cylinders adapted to be used in operating hydraulicbrakes. A

One of the objects of the invention is the elimination of unnecessaryand disadvantageous space between the pistons of apower actuator.

A further object of the invention is the provision of means for aidingin bleeding of hydraulic brake systems.

v A further object of the invention is the elimination of space whichwould otherwise trap unwanted air in hydraulic brake systems.

Furtherobjects and features of the invention will be apparent after areading of the subjoined l6 specification and claims and after aconsideration of the accompanying drawings, in which:

Figure 1 is a view partially in side elevation and partially in sectionshowing a brake constructed according to my invention;

m Figure 2 is a fragmentary sectional view of a portion of the brakeshown in Figure 1;

Figure 3 is a fragmentary sectional view of a modified form of wheelcylinder;

Figure 4 is a view similar to Figure 3 showing 35 another modified formof wheel cylinder;

Figure '5 is a view similar to Figures 3 and 4 showing another modifiedform of wheel cylinder; and

Figures 6, 7, 8 and 9 are views all similar to 30 Figures 3, 4 and 5showing other modified forms a of wheel cylinders.

Referring in detail t'o-the drawings, it may be seen that I have shown abrake comprising a drum 10, a backing plate l2, shoes l4 and I6 and aarranged to act upon one of the shoes I and I8.

5 It may be noted that the piston is provided with a wear plate 24 whichcontacts with an extension 26 of the shoe I4 and that the piston 22 isarranged to act against a cap 28 which has threaded into it a plug 30 onwhich the extension go 32 of the shoe It bears. It may be further notedthat the cap 28 is adapted to anchor upon the end of the cylinder casel9 and thusabsorb the torque of braking when the brake is actuatedwhilethe drum is rotating in.a' counterclockwise I; direction. It may befurther noted the'anchoring position as well as the return position ofthe shoe It may be adjusted by rotation of the cap 28'. Opposite to thecylinder I8 is another cylinder similar thereto also having its longi-'tudinal axis arranged vertical. By means of a 5 cap similar to the cap28 the anchoring and return positions of the shoe it may also beadjusted. In braking when the drum is rotating in the clockwisedirection the shoes anchor on the anchor H and a corresponding anchorpositioned adjacent the hidden end of the shoe it.

Each of the cylinders is provided with an inlet opening 34 and a bleedopening 36 and each of the pistons 20 and 22 is provided with a. rubberpacking such as 38 and 40. interposed between the packings 38 and I0 isa spring 4! for maintaining the packings in contact with, the pistons.

It may be seen that the packings 38 and 40 are each formed with anannular lip 42 extending inward of the cylinder and contacting with the20 walls of the cylinder and are each also provided with a circularcentral portion 46 so as to substantially fill the space between the twocups.

-Thus the space above the bleed opening 36 in which air might be trappedis substantially elimas inated.

In Figure 3 the cylinder H8 is formed with inlet opening I34 and bleedopening M6 and is provided with pistons I20 and M2 which arerespectively. These cup shaped packings are also ,formed with annularlips I42 and are provided with central metallic blocks 8 Zor eliminatingthe greater part of the space between the cups.

The spring I is provided for obvious reasons.

In the form shown in Figure 4 the cylinder 2m is formed with inletopening 236 and bleed.

opening 236 and is provided with pistons 225i and v 222 each providedwith an annular cup washer or packing such as 238 and 240. Each of thesea packings has an annular lip 262. The pistons 22d and 222 each have acentral projection 2 which extends through its associated cup and whichtogether substantially fill the space between the cups. a

In Figure'5 the cylinder 8" is formed with inlet opening 334 and bleedopening 366 and is provided with pistons 320 and 322, each of which isprovided with rubber washers such as 338 and 340 respectively. Thesewashers are provided so with annular lips 342 and are formed with acentral inwardly. extending portion 3 molded so as to fit around aknob-like extension 2 of the associated piston.

In the arrangement shown in Figure 6 there ll inder 5| 8 is providedwith pistons 520 and 522.

and is formed with an inlet opening 534 and a bleed opening 536. Thepistons 528 and 522 are provided with annular packings 538 and 540respectively. The packings 538 and 540 are formed with annular ups 542and the pistons 52a and 522 are provided with central extensions formingblocks 544 which substantially fill the space between the packings. Aspring 5 is interposed between the blocks 544.

In the arrangement shownin Figure 8 the cylinder 6| 8 is provided withpistons 620 and 622 and is formed with an inlet opening 634 and a bleedopening 636. The pistons 620 and 622 are provided with packing cups 638and 640 respectively. Each of the cups 638 and 640 is formed with anannular rim or lip 642 and there are provided a pair of metallic blocks644 interposed between two packing cups for substantially filling thespace therebetween. Interposed between the two blocks 644 is a spring 6.

The arrangement shown in Figure 9 corresponds substantially to thatshown in Figure 8.

The cylinder H8 is provided with pistons I28 and I22 and is formed withan inlet opening I34 and a bleed opening I36. Each of the pistons ispro-- vided with an annular seal such as I38 and I40 respectively. Eachof these annular packings is formed with an annular lip I42 andinterposed between the packings I38 and I48 are a pair of blocks I44 anda spring I4I. Extending through the block I44 and forming a guide forthe spring 'I4l are pin-like projections 146 formed on the pistons I28and I22.

It is to be understood that the above-described embodiments of myinvention are for the purpose of illustration only and various changesmay-be made therein without departing from the spirit and scope of theinvention.

'1 claim:

1. In a hydraulic braking system in which vertical actuating means isused, an actuating cylin- .der having its axis positioned substantiallyvertically being formed with an inlet opening and al bleed opening, andprovided with a pair of pistons'e ach formed with an extension graduallyincreasing in diameter toward the central portion of the cylinder, and'asealing packing memher for each of said pistons, said packlngs eachbeing formed with an annular lip contacting with.

a bleed opening, and provided with a pair or.

pistons each formed with an extension gradually increasing in diametertoward the central portion of the cylinder, and an annular sealingpacking member for each of said pistons, said packings each being formedwith an annular lip. contacting with the sides of the cylinder andhaving a space formed between the edges of said lip through which thepiston extensions extend and each being provided with a central membersubstantially filling said space, said centralmember extending towardthe center of said actuat ing cylinder at least as far as the plane ofthe annular lip.

3. In a hydraulic braking system in which a vertical actuating means isused, an actuating cylinder having its axis positioned substantiallyvertically, being formed with ,an inlet opening and a bleed opening, a.pair of piston means for said cylinder, one said piston means beingpositioned above the other and each said piston means comprising apacking formed with an annular lip contacting with the sides of thecylinder and a central metallic portion substantially filling the spacewithin said annular lip gradually increasing in diameter toward the tipof said lip.

4. In a hydraulic braking system in which a vertical actuating means isused, an actuating cylinder having its axis positioned substantiallyvertically, being formed with an inlet opening and a bleed opening, apair of piston means for said cylinder, one said piston means beingpositioned above the other and each said piston means comprising a cuppacking formed with an annular lip contacting with the sides of thecylinder and a central metallic portion in front of said cupsubstantially filling the space within said cup gradually increasing indiameter toward the tip 01 said lip.

LUDGER E. LA Barn. M

